Spark plug



l. A. WEAVER.

Jan 23, 1923.

SPARK PLUG.

FILED MAR. 1920.

v VHIHIIHII'IIHH ,2,

- /u ar'olo'rt- 0% Q. 212W] a/ kw Patented Jan. 23, 1923.

IRA A; WEAVER, or SPRINGFIE D; ILLINO IS, ASSIGITORv TO TI-IE RVEAVEB MANUFAQ-.

monmecomranr, or SPRINGFIELD, ILLINOIS, A CORPORATION/Q1"ILLINGIS.

, SPAR}! mine.

Tod'ZZw/iom it may concern Be it known that I, IRA 'ASWVnavnma citizen of the United States,residing atSpring- 'fielchin' the county ofSan'ganion and State (it-Illinois, have invented certain new and useful Improvements in Spark Plugs, of which the following is a specification, My invention concerns fcleanable sparkplugs for use with internal combustion engines or motors whichare'subje-ct toniore or less fouling and possible short-circuiting by 'the residual carbon deposited the-reon re- 'maining from the "lubricating oil and the fuel One object of the invention is the mounting of one of the terminals jor sparking points in such a Way, as by; plvotlng or hang. ing it, so that it may be temporarily sh fted I away from its companion thus-re1idering easily accessible the spaces "or cavities of the plug most likely to contain or harborthe objectionable carbon and possibly otlleliifellb is unreliable and maybe wholly misleading.

i-'\ccordingly, one or the prime purposes of this intention is to provide a spark-plug structure which will, permit it to" be tested in the open air in such a way that if the test is satisfactory there is all reasonable assurance "that the 13111; .will function properly when subject to the engine-cylinder compression This maybe done by'making one er" the 'sparlc plug' Wires or points adjustable so that the gap between the points may be lengthened during the test to compensateftor the "absenc of compression. 1f the arc jumps such test ga-p" in 'theopen' air there is reasonable certainty that it will properly jump=the shorter service gap under compression conditions. Accordinglyfin theimproved plug,-the'movable terminal has two definitekpositio ns ,"{the one forming ashorter seimice-gap with the complementary terminal and the other a longer test-gap, the mov- Application'fiIedJl Iarch' 1, 1920. Serial aim-362,395.

able terminal being also capable of'being shifted still further away from the compan-v ion fixed terminal toifacilitate the cleaning of the plug as'a whole.

I To enable thoseskilledin thisi art to fully understand this inventioIrI haveillustrated embodiments of the same in theaacco-rnpany ing drawing forming-a part of this specificationand to which reference'shou-ld be had in connection with the tollowing detailed description. I

In this drawing, throughout the several views of such sheet,'like reterencecharacters etc! to the same parts.

i igure l is an elevation of thepreterred embodiment of the -1nvention;

Figure 2 is anenlarged elevation oi the end portionof= such sp'ark p'lug with the outer threaded metal sleeve-or skirt broken away to Inore clearly' illustrate the internal construction;

F'gure '3 isa bottom plan view of the structure of Figure 2;

"Figure 4 is fragmentary elevation of the lower. portion 'ofthe-plug showing -m'ore clearly the pivotal or hinge mounting-of the 'novable terminal; i Figure 5 is a'fragmentary elevationof the other side ofthe' plug; i

Figure 6 showspartly in elevation and partially in section a' differenti orm of sparkplug incorporating a modified 'structure 5 and shows the plug screwed into position-in a portion ofthe engine or I-notor yand a Figure 7 isa bottom plan viewo'fi the plug ofFigure' 6 'remox e'd t'rom the engineiarid",

with the movable terminal "temporarily swung away'to facilitate the carbon cleaning operation.

Referring first to the species of j-plugs illustrated in Figures 1 to 5 inclusive, it will be observed that the device comprises hollow metal main-body 10 having a =heX-' agonal portion 11, a cylindrical part 12;and an 'externally threaded skirt ---secti on 13 adaptedrto be screwed into a correspond- 'ingly-threade'd hole inthe engine' or motor, a flat shoulder l l being presentb'etween the larger part 12 and the portion '13 "of reduced diameter. Such body receives 'within it a porcelain or other 7 suitable insulation sleeve 15 covering and protecting inner v beyond f' the porcelain' aelement tofforin =11 spark terminal; and at its other p rotruding end is fitted with the ordinary; means 17 for...

.ordinary spark-plug, but it may be noted that the hole 18 through the'niain metal making one portion 19 of its wall thicker than the diametricallyppposite portion 20 of the same wall.- The complementary electriclterminal 21 comprises a-bent spring wire tofu-shape with one leg 22 longer than I the other leg 23, the intermediate connects ..-ing portionbeing somewhat bowedfat 24 as:

illustrated in Figure3. The part '22 is desirably copper-coated to prevent undue or excessive corrosion andqoccupies a cylindrr.

cal-hole orubearing 25' of the same diameter. drilled lengthwise the plug fromits end H 1 in the thickest part 190tthe 'eccentric threaded skirt. oi'-' apron. Suchfhole communicates at its upper end with arelativelyshallow cavity 26 of large-bore extended radially inwardly inthe part 19 and in this recess the end sectlongof-the, wire'-is-bent laterally or crimped-at 27 toretain the wire' from lengthwise movement in its bearing 25: As isshown most, clearly iIl'ElgllI'6S 2, 3', and 5, the edge of the thinner partQO ofthe metal sleeve 13 is supplied with two spaced notchesy or depressions 28 land 29 I either one of which is adapted to receiv the end ofthe' leg-23 of the terminal to retain it .in fixed position until intentionally shifted 3 5 movement, f

'therefrom, it being'understood that the terminal has'suificient resiliency to permit such The construction is such when the part2?) of the movable terminal is in the retaining notch 28, the spark-gap or arcing space between the/terminals will be that c Y which is proper for service and hence, may

be aptly termed, the servicergapp When the 'sameportion of'the-Ishiftable terminal is win the other depression29, as is indicated in dotted lines in Figure ,3, and in jtull lines "in Figure 5, the spark-gap .or so-called testgap between the terminals will be somewhat greater andwill have such relation. to

the service-gap that ifthe plug will are properly. over such test-gap in the open at mosphereit will spark, efficiently over the service-gap whenin, placein the engine and subjected togthe usual explosive-mixture" Compression; p 1 4 v i If it is desired to clean the-plug, the. oscillatory terminal maybe rocke'd'fto ex- .f treme outer position, asfisalso depicted in 1d0tted1lins in Figure 3, thereby exposing the terminals themselves for cleaning, but

more especially the space between the porcelain insulator 15c and the inner surface of.

' the threadedskirt or apron portion 13.-

v =-The readily-accessible cavity or aperture 26 afi'ords easy means for the introduction of a suitable tool to -provi de-f the retaining outer terminal is firmly and se'curely held in] proper; position without dan crimp ih the' terminal wire when the latter is first inserted in place, and for straightening out such bend if desirecl to permit the with not embodythe feature of test andservice gaps specified above, butitf' has one offits' drawal of/the wire ancl fits v p substitution-by another. body is eccentric "to-"its outer surfaces, thus terminals movable tofacilitate the cleaning other figures except that, instead of incorporating theterminal 21and its mounting and -.retaining or position determining 31' inwhich ai l'aterally bent journal part 32 operation. The plug is like the one ofthe i of they-movable"terminal 33-is rockingly mountechan intermediate portion of the terminal normally occupying the groove 30 and retained therein by the wall of the; e'n- I allas is tullyindicated inFigure Und ginevor. motorin which the plug is screwed,

these conditions. there is, abnormal service'- gap ofcorrectlength between the ends of,

the two terminals, but as soon, the plug is removed from theengine its outer tern-c m nal' 1s] free to be swung away from the inner terminal sufiiciently to give plenty of When the 1 plug is in service, however, such ment for maladjustment.

platedto reduce or eliminate the tendency to corrosionat such point, or, ifp'referred. i a sleeve of suitable metal different from that of'the apron or skirt of the plug,jmay be I inserted c in the' -,bearing aperture thereof, thus; operating as a bushing of. different metal between the movable-terminal and the main-body of the plug.

room for'the carbon-remov ing"operation. f--

' ger of dislodg 3 In both of these embodiments thegportion Y 0f the movable term-inal'in contact-with the metal sleeve may beucopper' or otherwise example only.; It will be understood, there- 1' "fore, that many othenstructures differing vfrom these more or lessm mechanical details .may be madev incorporating this invention without departing from the; substanceand' essence of thelatterand without-the sacrifice of any of its substantial benefits and advantages, Forexamplepit isnotnecessarv'that V the one terminal be movable toward and from p the other so (long, as "the, -pIug inay'be caused to have aplurality of gapsof differe'nt lengths; I 1 p I 7 tomatically in two'predetermined I claim: I

1. A spark-plug for internal-combustion engines in which one of the terminals is rockingly adjustable relatively to the companion terminal to provide a plurality of spark-gaps of predetermined different lengths between the terminals, substantially as described.

2. A spark-plug for internal-combustion engines having a pair of terminals one o which is movable toward and from the companion terminal with means to lock it aupositions, the one position forming a service-ga. and the-other position a test-gap of di erent length, substantially as described.

3. A spark-plug for internal-combustion engines having a pair of terminals movably mounted relatively. to one another to pro 1 terminals,

vide a predetermined service-gap for'use under compression and a longer predetermined test-gap for use in the open atmosphere of a length'to compensate for the absence of compression, with means to lock the terminals automatically in" thetwo service and test positions, substantially as described; j i v A. A spark-plug for internal-combustion engines having a terminal, a companion terminal rockingly'mounted in the plug to vary the length of spark-gap between the and a'layer of metal difierent from that of said movable terminal interposed between the same and its-bearing in the plug, substantially asdescribed.

' 5. A spark-plug for internal-combustion engines having in combination a terminal, a depending threaded skirt with a longitudinal bearing therein and a plurality of notches, and a movable terminal rocklngly' mounted in said bearing and having a portion adapted to engage any one of said notches, to provide the thickness with a longitudinal bearing theref in at its thickest part and a plurality of notches therein at its thinner part and a movable terminal rockingly mounted in spark-plug with a I plurality of spark-gaps of different lengths,

said bearing'and having a portion adapted toengage any one of said notches to provide the spark-plug with a plurality of spark-gaps of different lengths, substantially as described.

7. A spark-plug for engines a depending threaded skirt with a longituinternal-combustion dinal bearing therein and a plurality of notches in its'edge, a U-shaped movable terminal' having one leg thereof rockingly -mounted in saidv vbearing and the other leg adapted to engage any one of said notches to provide the spark-plug with a plurality having 1n combination a terminal,

of spark-gaps or different lengths, substan- I tially as described.

8. A spark-plug for internal-combustion engines having a lengthwise channel in its skirt rockingly accommodating one of the spark-plug terminals, said plug having an aperture intersecting said channel to facilitate the securing of the. terminal in said channel and its removal therefrom by givingaccess thereto to permit bending of the terminal wire for its retention in place or A to permit its removal fromthe plug, substantially as described. r

. l A A. WEAVER. 

